Boc-L-3-Nitrophenylalanine is a protected derivative of L-Phenylalanine (P319415), and is used in the photocleavage of polypeptide backbones. L-Phenylalanine is an essential amino acid. L-Phenylalanine is biologically converted into L-tyrosine, another one of the DNA-encoded amino acids, which in turn is converted to L-DOPA and further converted into dopamine, norepinephrine, and epinephrine.